I always use the top 3 keywords related to the website niche and another 3-5 sub keywords that will drive organic searches to the website
I used to use Keyword Discovery and Word Tracker for building my PPC campaigns 3 years ago. Also worked with Keyword Spy and Spyfu. In the recent times, I use Market Samurai and Keyword Blaze. Google Keyword Tool is always there for quick research.
Google Keyword tool and Traffic Travis as a combination are great for finding the right keywords for any niche. Once you find a good "exact" match in google keyword tool, take that keyword, plug it in traffic travis to see if how much competition it has in the top ten. If you think you can compete to get into the top 10 then you have your perfect keyword. The great thing is that both tools are absolutely free!
Awsome topic man. I will have to say GOOGLE keyword tool. Ive spent more time in this tool then others because when I 1st got into IM i had no money so this was all I had, so I had. Ive seen daily changes over and over, I found all kinds of tricks to drill down keywords. when I started making sales from SEO, this is the tool that I had to thank for it. it will always have my respect lol.
i only know of adwords keyword tool but i have been looking for one which does real time or yesterdays searches so we can see querys rise/fall faster than last month
ezarticlelink.com is a place where you can put a keyword and it tell you in seconds if you can rank for it. Get some keywords from google and just type them in. For best results get long tail..
never use any other than google's kt, perhaps market samurai or skca worth to try, later as soon as i have some cashes